1. Field of the Invention
This invention pertains in general to data encryption using computer systems and more particularly to rights management for digital content.
2. Background Art
Broadband networking technology has become commonplace. For example, many households receive digital television signals via broadband cable and satellite distribution systems. Similarly, many households connect to the Internet via broadband connections provided by technologies such as cable modems and digital subscriber lines (DSL). Furthermore, digital radio and broadcast television technologies, as well as wireless broadband Internet access are also becoming more prevalent.
This pervasive access to broadband networking technology has made it easier for the typical consumer and other computer users to receive high-quality digital content. This content includes, for example, audio content, such as music, visual content, such as photographs, and multimedia content such as television programs and movies. Consumers also receive digital content via physical media such as compact disks (CDs) and DVDs.
The broadband network technology also makes it easier for consumers to share digital content with others. This sharing has led to an increase in the role of digital rights management (DRM) technology. In general, publishers and other content distributors seek to use DRM technology to provide authorized consumers with access to digital content while simultaneously preventing unauthorized consumers from accessing it.
Existing DRM schemes are flawed for a variety of reasons. For example, some DRM schemes use a secret key to encrypt content. The encrypted content is publicly available, but the secret keys are distributed to only the consumers authorized to use the keys to access the content. Due to the nature of content distribution, it is impractical to utilize different keys for different consumers and/or different content. Therefore, the entire DRM scheme is compromised if the secret keys become publicly available through compromising consumer equipment or other means.
Some DRM technologies attempt to protect the secret key by storing it in a tamper-proof device that theoretically cannot be breached by consumers. However, history has demonstrated that any tamper-proof device distributed to consumers will eventually be defeated and the secret keys will become available. For example, the secret keys utilized to protect DVDs were discovered only a few years after DVDs and corresponding DVD players became publicly available.
Therefore, there is a need in the art for a content protection scheme that does not rely on secret keys that are distributed to consumers.